Flexible, resilient, polyurethane foams can be made by reacting a polyol and a polyisocyanate in the presence of a blowing agent. The foams can be used for a wide variety of purposes, such as carpet underlay, textile innerlining, furniture padding, crash pads in automobiles, mattresses, pillows and insulation. Polyurethane foams can burn readily when ignited. The present invention provides a method whereby there can be manufactured a flexible, resilient, polyurethane foam of reduced tendency to produce burning embers when burned. This is an important advantage, inasmuch as the spreading of the fire is reduced.